/Engine/Source/Runtime/UMG/Public/Blueprint/UserWidget.h
Called during drag and drop when the the mouse is being dragged over a widget.
'true' to indicate that you handled the drag over operation. Returning 'false' will cause the operation to continue to bubble up.
bool OnDragOver ( [FGeometry](API\Runtime\SlateCore\Layout\FGeometry) MyGeometry, [FPointerEvent](API\Runtime\SlateCore\Input\FPointerEvent) PointerEvent, [UDragDropOperation](API\Runtime\UMG\Blueprint\UDragDropOperation) * Operation )